Question

S-phase arrest in response to glutamine deprivation in KRas-driven cancer cells can be reversed by aspartate.

A) True   

B) False

Answer 1

Solution:-

The arrest of KRas-driven cancer cells in S-phase upon glutamine deprivation is due to the lack of deoxynucleotides needed for DNA synthesis. The lack of deoxynucleotides causes replicative stress leading to activation of the ataxia telangiectasia and Rad3-related protein (ATR)-mediated DNA damage pathway, which arrest cells in S-phase.

The key metabolite generated from glutamine utilization was aspartate which is generated from the transaminase reaction whereby glutamine derived glutamate is converted to alpha-ketoglutarate with the concomitant conversion of oxaloacetate to aspartate. Aspartate is the critical metabolite for both purine ana pyrimidine nucleotide biosynthesis.

So, the correct option is (a) True.